1 files changed, 544 insertions, 0 deletions

diff --git a/src/libmsc/sms_queue.c b/src/libmsc/sms_queue.c
new file mode 100644
index 000000000..dc7f6e8c6
--- /dev/null
+++ b/src/libmsc/sms_queue.c
@@ -0,0 +1,544 @@
+/* SMS queue to continously attempt to deliver SMS */
+/*
+ * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * The difficulty of such a queue is to send a lot of SMS without
+ * overloading the paging subsystem and the database and other users
+ * of the MSC. To make the best use we would need to know the number
+ * of pending paging requests, then throttle the number of SMS we
+ * want to send and such.
+ * We will start with a very simple SMS Queue and then try to speed
+ * things up by collecting data from other parts of the system.
+ */
+
+#include <openbsc/sms_queue.h>
+#include <openbsc/chan_alloc.h>
+#include <openbsc/db.h>
+#include <openbsc/debug.h>
+#include <openbsc/gsm_data.h>
+#include <openbsc/gsm_04_11.h>
+#include <openbsc/gsm_subscriber.h>
+#include <openbsc/signal.h>
+
+#include <osmocom/core/talloc.h>
+
+#include <osmocom/vty/vty.h>
+
+/*
+ * One pending SMS that we wait for.
+ */
+struct gsm_sms_pending {
+	struct llist_head entry;
+
+	struct gsm_subscriber *subscr;
+	unsigned long long sms_id;
+	int failed_attempts;
+	int resend;
+};
+
+struct gsm_sms_queue {
+	struct osmo_timer_list resend_pending;
+	struct osmo_timer_list push_queue;
+	struct gsm_network *network;
+	int max_fail;
+	int max_pending;
+	int pending;
+
+	struct llist_head pending_sms;
+	unsigned long long last_subscr_id;
+};
+
+static int sms_subscr_cb(unsigned int, unsigned int, void *, void *);
+static int sms_sms_cb(unsigned int, unsigned int, void *, void *);
+
+static struct gsm_sms_pending *sms_find_pending(struct gsm_sms_queue *smsq,
+						struct gsm_sms *sms)
+{
+	struct gsm_sms_pending *pending;
+
+	llist_for_each_entry(pending, &smsq->pending_sms, entry) {
+		if (pending->sms_id == sms->id)
+			return pending;
+	}
+
+	return NULL;
+}
+
+static int sms_is_in_pending(struct gsm_sms_queue *smsq, struct gsm_sms *sms)
+{
+	return sms_find_pending(smsq, sms) != NULL;
+}
+
+static struct gsm_sms_pending *sms_subscriber_find_pending(
+					struct gsm_sms_queue *smsq,
+					struct gsm_subscriber *subscr)
+{
+	struct gsm_sms_pending *pending;
+
+	llist_for_each_entry(pending, &smsq->pending_sms, entry) {
+		if (pending->subscr == subscr)
+			return pending;
+	}
+
+	return NULL;
+}
+
+static int sms_subscriber_is_pending(struct gsm_sms_queue *smsq,
+				     struct gsm_subscriber *subscr)
+{
+	return sms_subscriber_find_pending(smsq, subscr) != NULL;
+}
+
+static struct gsm_sms_pending *sms_pending_from(struct gsm_sms_queue *smsq,
+						struct gsm_sms *sms)
+{
+	struct gsm_sms_pending *pending;
+
+	pending = talloc_zero(smsq, struct gsm_sms_pending);
+	if (!pending)
+		return NULL;
+
+	pending->subscr = subscr_get(sms->receiver);
+	pending->sms_id = sms->id;
+	return pending;
+}
+
+static void sms_pending_free(struct gsm_sms_pending *pending)
+{
+	subscr_put(pending->subscr);
+	llist_del(&pending->entry);
+	talloc_free(pending);
+}
+
+static void sms_pending_resend(struct gsm_sms_pending *pending)
+{
+	struct gsm_sms_queue *smsq;
+	LOGP(DLSMS, LOGL_DEBUG,
+	     "Scheduling resend of SMS %llu.\n", pending->sms_id);
+
+	pending->resend = 1;
+
+	smsq = pending->subscr->group->net->sms_queue;
+	if (osmo_timer_pending(&smsq->resend_pending))
+		return;
+
+	osmo_timer_schedule(&smsq->resend_pending, 1, 0);
+}
+
+static void sms_pending_failed(struct gsm_sms_pending *pending, int paging_error)
+{
+	struct gsm_sms_queue *smsq;
+
+	LOGP(DLSMS, LOGL_NOTICE, "Sending SMS %llu failed %d times.\n",
+	     pending->sms_id, pending->failed_attempts);
+
+	smsq = pending->subscr->group->net->sms_queue;
+	if (++pending->failed_attempts < smsq->max_fail)
+		return sms_pending_resend(pending);
+
+	sms_pending_free(pending);
+	smsq->pending -= 1;
+	sms_queue_trigger(smsq);
+}
+
+/*
+ * Resend all SMS that are scheduled for a resend. This is done to
+ * avoid an immediate failure.
+ */
+static void sms_resend_pending(void *_data)
+{
+	struct gsm_sms_pending *pending, *tmp;
+	struct gsm_sms_queue *smsq = _data;
+
+	llist_for_each_entry_safe(pending, tmp, &smsq->pending_sms, entry) {
+		struct gsm_sms *sms;
+		if (!pending->resend)
+			continue;
+
+		sms = db_sms_get(smsq->network, pending->sms_id);
+
+		/* the sms is gone? Move to the next */
+		if (!sms) {
+			sms_pending_free(pending);
+			smsq->pending -= 1;
+			sms_queue_trigger(smsq);
+		} else {
+			pending->resend = 0;
+			gsm411_send_sms_subscr(sms->receiver, sms);
+		}
+	}
+}
+
+static struct gsm_sms *take_next_sms(struct gsm_sms_queue *smsq)
+{
+	struct gsm_sms *sms;
+
+	sms = db_sms_get_unsent_by_subscr(smsq->network, smsq->last_subscr_id, 10);
+	if (sms) {
+		smsq->last_subscr_id = sms->receiver->id + 1;
+		return sms;
+	}
+
+	/* need to wrap around */
+	smsq->last_subscr_id = 0;
+	sms = db_sms_get_unsent_by_subscr(smsq->network,
+					  smsq->last_subscr_id, 10);
+	if (sms)
+		smsq->last_subscr_id = sms->receiver->id + 1;
+	return sms;
+}
+
+/**
+ * I will submit up to max_pending - pending SMS to the
+ * subsystem.
+ */
+static void sms_submit_pending(void *_data)
+{
+	struct gsm_sms_queue *smsq = _data;
+	int attempts = smsq->max_pending - smsq->pending;
+	int initialized = 0;
+	unsigned long long first_sub = 0;
+	int attempted = 0, rounds = 0;
+
+	LOGP(DLSMS, LOGL_DEBUG, "Attempting to send %d SMS\n", attempts);
+
+	do {
+		struct gsm_sms_pending *pending;
+		struct gsm_sms *sms;
+
+
+		sms = take_next_sms(smsq);
+		if (!sms) {
+			LOGP(DLSMS, LOGL_DEBUG, "Sending SMS done (%d attempted)\n",
+			     attempted);
+			break;
+		}
+
+		rounds += 1;
+		LOGP(DLSMS, LOGL_DEBUG, "Sending SMS round %d\n", rounds);
+
+		/*
+		 * This code needs to detect a loop. It assumes that no SMS
+		 * will vanish during the time this is executed. We will remember
+		 * the id of the first GSM subscriber we see and then will
+		 * compare this. The Database code should make sure that we will
+		 * see all other subscribers first before seeing this one again.
+		 *
+		 * It is always scary to have an infinite loop like this.
+		 */
+		if (!initialized) {
+			first_sub = sms->receiver->id;
+			initialized = 1;
+		} else if (first_sub == sms->receiver->id) {
+			LOGP(DLSMS, LOGL_DEBUG, "Sending SMS done (loop) (%d attempted)\n",
+			     attempted);
+			sms_free(sms);
+			break;
+		}
+
+		/* no need to send a pending sms */
+		if (sms_is_in_pending(smsq, sms)) {
+			LOGP(DLSMS, LOGL_DEBUG,
+			     "SMSqueue with pending sms: %llu. Skipping\n", sms->id);
+			sms_free(sms);
+			continue;
+		}
+
+		/* no need to send a SMS with the same receiver */
+		if (sms_subscriber_is_pending(smsq, sms->receiver)) {
+			LOGP(DLSMS, LOGL_DEBUG,
+			     "SMSqueue with pending sub: %llu. Skipping\n", sms->receiver->id);
+			sms_free(sms);
+			continue;
+		}
+
+		pending = sms_pending_from(smsq, sms);
+		if (!pending) {
+			LOGP(DLSMS, LOGL_ERROR,
+			     "Failed to create pending SMS entry.\n");
+			sms_free(sms);
+			continue;
+		}
+
+		attempted += 1;
+		smsq->pending += 1;
+		llist_add_tail(&pending->entry, &smsq->pending_sms);
+		gsm411_send_sms_subscr(sms->receiver, sms);
+	} while (attempted < attempts && rounds < 1000);
+
+	LOGP(DLSMS, LOGL_DEBUG, "SMSqueue added %d messages in %d rounds\n", attempted, rounds);
+}
+
+/**
+ * Send the next SMS or trigger the queue
+ */
+static void sms_send_next(struct gsm_subscriber *subscr)
+{
+	struct gsm_sms_queue *smsq = subscr->group->net->sms_queue;
+	struct gsm_sms_pending *pending;
+	struct gsm_sms *sms;
+
+	/* the subscriber should not be in the queue */
+	OSMO_ASSERT(!sms_subscriber_is_pending(smsq, subscr));
+
+	/* check for more messages for this subscriber */
+	sms = db_sms_get_unsent_for_subscr(subscr);
+	if (!sms)
+		goto no_pending_sms;
+
+	/* No sms should be scheduled right now */
+	OSMO_ASSERT(!sms_is_in_pending(smsq, sms));
+
+	/* Remember that we deliver this SMS and send it */
+	pending = sms_pending_from(smsq, sms);
+	if (!pending) {
+		LOGP(DLSMS, LOGL_ERROR,
+			"Failed to create pending SMS entry.\n");
+		sms_free(sms);
+		goto no_pending_sms;
+	}
+
+	smsq->pending += 1;
+	llist_add_tail(&pending->entry, &smsq->pending_sms);
+	gsm411_send_sms_subscr(sms->receiver, sms);
+	return;
+
+no_pending_sms:
+	/* Try to send the SMS to avoid the queue being stuck */
+	sms_submit_pending(subscr->group->net->sms_queue);
+}
+
+/*
+ * Kick off the queue again.
+ */
+int sms_queue_trigger(struct gsm_sms_queue *smsq)
+{
+	LOGP(DLSMS, LOGL_DEBUG, "Triggering SMS queue\n");
+	if (osmo_timer_pending(&smsq->push_queue))
+		return 0;
+
+	osmo_timer_schedule(&smsq->push_queue, 1, 0);
+	return 0;
+}
+
+int sms_queue_start(struct gsm_network *network, int max_pending)
+{
+	struct gsm_sms_queue *sms = talloc_zero(network, struct gsm_sms_queue);
+	if (!sms) {
+		LOGP(DMSC, LOGL_ERROR, "Failed to create the SMS queue.\n");
+		return -1;
+	}
+
+	osmo_signal_register_handler(SS_SUBSCR, sms_subscr_cb, network);
+	osmo_signal_register_handler(SS_SMS, sms_sms_cb, network);
+
+	network->sms_queue = sms;
+	INIT_LLIST_HEAD(&sms->pending_sms);
+	sms->max_fail = 1;
+	sms->network = network;
+	sms->max_pending = max_pending;
+	osmo_timer_setup(&sms->push_queue, sms_submit_pending, sms);
+	osmo_timer_setup(&sms->resend_pending, sms_resend_pending, sms);
+
+	sms_submit_pending(sms);
+
+	return 0;
+}
+
+static int sub_ready_for_sm(struct gsm_network *net, struct gsm_subscriber *subscr)
+{
+	struct gsm_sms *sms;
+	struct gsm_sms_pending *pending;
+	struct gsm_subscriber_connection *conn;
+
+	/*
+	 * The code used to be very clever and tried to submit
+	 * a SMS during the Location Updating Request. This has
+	 * two issues:
+	 *   1.) The Phone might not be ready yet, e.g. the C155
+	 *       will not respond to the Submit when it is booting.
+	 *   2.) The queue is already trying to submit SMS to the
+	 *	 user and by not responding to the paging request
+	 *	 we will set the LAC back to 0. We would have to
+	 *	 stop the paging and move things over.
+	 *
+	 * We need to be careful in what we try here.
+	 */
+
+	/* check if we have pending requests */
+	pending = sms_subscriber_find_pending(net->sms_queue, subscr);
+	if (pending) {
+		LOGP(DMSC, LOGL_NOTICE,
+		     "Pending paging while subscriber %llu attached.\n",
+		      subscr->id);
+		return 0;
+	}
+
+	conn = connection_for_subscr(subscr);
+	if (!conn)
+		return -1;
+
+	/* Now try to deliver any pending SMS to this sub */
+	sms = db_sms_get_unsent_for_subscr(subscr);
+	if (!sms)
+		return -1;
+	gsm411_send_sms(conn, sms);
+	return 0;
+}
+
+static int sms_subscr_cb(unsigned int subsys, unsigned int signal,
+			 void *handler_data, void *signal_data)
+{
+	struct gsm_subscriber *subscr = signal_data;
+
+	if (signal != S_SUBSCR_ATTACHED)
+		return 0;
+
+	/* this is readyForSM */
+	return sub_ready_for_sm(handler_data, subscr);
+}
+
+static int sms_sms_cb(unsigned int subsys, unsigned int signal,
+		      void *handler_data, void *signal_data)
+{
+	struct gsm_network *network = handler_data;
+	struct sms_signal_data *sig_sms = signal_data;
+	struct gsm_sms_pending *pending;
+	struct gsm_subscriber *subscr;
+
+	/* We got a new SMS and maybe should launch the queue again. */
+	if (signal == S_SMS_SUBMITTED || signal == S_SMS_SMMA) {
+		/* TODO: For SMMA we might want to re-use the radio connection. */
+		sms_queue_trigger(network->sms_queue);
+		return 0;
+	}
+
+	if (!sig_sms->sms)
+		return -1;
+
+
+	/*
+	 * Find the entry of our queue. The SMS subsystem will submit
+	 * sms that are not in our control as we just have a channel
+	 * open anyway.
+	 */
+	pending = sms_find_pending(network->sms_queue, sig_sms->sms);
+	if (!pending)
+		return 0;
+
+	switch (signal) {
+	case S_SMS_DELIVERED:
+		/* Remember the subscriber and clear the pending entry */
+		network->sms_queue->pending -= 1;
+		subscr = subscr_get(pending->subscr);
+		sms_pending_free(pending);
+		/* Attempt to send another SMS to this subscriber */
+		sms_send_next(subscr);
+		subscr_put(subscr);
+		break;
+	case S_SMS_MEM_EXCEEDED:
+		network->sms_queue->pending -= 1;
+		sms_pending_free(pending);
+		sms_queue_trigger(network->sms_queue);
+		break;
+	case S_SMS_UNKNOWN_ERROR:
+		/*
+		 * There can be many reasons for this failure. E.g. the paging
+		 * timed out, the subscriber was not paged at all, or there was
+		 * a protocol error. The current strategy is to try sending the
+		 * next SMS for busy/oom and to retransmit when we have paged.
+		 *
+		 * When the paging expires three times we will disable the
+		 * subscriber. If we have some kind of other transmit error we
+		 * should flag the SMS as bad.
+		 */
+		switch (sig_sms->paging_result) {
+		case 0:
+			/* BAD SMS? */
+			db_sms_inc_deliver_attempts(sig_sms->sms);
+			sms_pending_failed(pending, 0);
+			break;
+		case GSM_PAGING_EXPIRED:
+			sms_pending_failed(pending, 1);
+			break;
+
+		case GSM_PAGING_OOM:
+		case GSM_PAGING_BUSY:
+			network->sms_queue->pending -= 1;
+			sms_pending_free(pending);
+			sms_queue_trigger(network->sms_queue);
+			break;
+		default:
+			LOGP(DLSMS, LOGL_ERROR, "Unhandled result: %d\n",
+			     sig_sms->paging_result);
+		}
+		break;
+	default:
+		LOGP(DLSMS, LOGL_ERROR, "Unhandled result: %d\n",
+		     sig_sms->paging_result);
+	}
+
+	return 0;
+}
+
+/* VTY helper functions */
+int sms_queue_stats(struct gsm_sms_queue *smsq, struct vty *vty)
+{
+	struct gsm_sms_pending *pending;
+
+	vty_out(vty, "SMSqueue with max_pending: %d pending: %d%s",
+		smsq->max_pending, smsq->pending, VTY_NEWLINE);
+
+	llist_for_each_entry(pending, &smsq->pending_sms, entry)
+		vty_out(vty, " SMS Pending for Subscriber: %llu SMS: %llu Failed: %d.%s",
+			pending->subscr->id, pending->sms_id,
+			pending->failed_attempts, VTY_NEWLINE);
+	return 0;
+}
+
+int sms_queue_set_max_pending(struct gsm_sms_queue *smsq, int max_pending)
+{
+	LOGP(DLSMS, LOGL_NOTICE, "SMSqueue old max: %d new: %d\n",
+	     smsq->max_pending, max_pending);
+	smsq->max_pending = max_pending;
+	return 0;
+}
+
+int sms_queue_set_max_failure(struct gsm_sms_queue *smsq, int max_fail)
+{
+	LOGP(DLSMS, LOGL_NOTICE, "SMSqueue max failure old: %d new: %d\n",
+	     smsq->max_fail, max_fail);
+	smsq->max_fail = max_fail;
+	return 0;
+}
+
+int sms_queue_clear(struct gsm_sms_queue *smsq)
+{
+	struct gsm_sms_pending *pending, *tmp;
+
+	llist_for_each_entry_safe(pending, tmp, &smsq->pending_sms, entry) {
+		LOGP(DLSMS, LOGL_NOTICE,
+		     "SMSqueue clearing for sub %llu\n", pending->subscr->id);
+		sms_pending_free(pending);
+	}
+
+	smsq->pending = 0;
+	return 0;
+}